Neutrophil Adhesion Cascade in Inflammation

Overview of Therapeutic Modulation

The American Society of Anesthesiologists recommends the use of volatile anesthetics, such as isoflurane and sevoflurane, to decrease neutrophil adhesion to human endothelial cells, which may provide beneficial effects in ischemic settings 1, 2

Neutrophils are the first and most lethal effector cells recruited to inflammation sites, where they deploy phagocytosis and oxidative burst mechanisms that destroy pathogens but also damage native tissues, according to the American Society of Anesthesiologists 1, 2
The inflammatory cascade in sepsis involves early release of proinflammatory cytokines, such as TNF-α, IL-1, IL-6, and IL-8, by epithelial cells, facilitating neutrophil and monocyte penetration into injured tissue 3
Activated neutrophils release reactive oxygen species, nitric oxide, hydrolytic enzymes, and additional proinflammatory cytokines, contributing to tissue damage and organ dysfunction 3

The American Journal of Respiratory and Critical Care Medicine suggests that chemokines, particularly IL-8, induce neutrophil chemotaxis and activation, especially when combined with leukotriene B4 or platelet-activating factor 4
Hypertonic saline blunts neutrophil activation and alters cytokine production profiles, reducing TNF-α while increasing anti-inflammatory IL-10 and IL-1ra, as reported in Anaesthesia 5
Reduced neutrophil migration and activation, lung-specific polymorphonuclear activation reduction, and improved microcirculatory flow are key mechanisms of hypertonic saline beyond simple volume expansion 5

The American Society of Anesthesiologists recommends considering hypertonic saline resuscitation in hemorrhagic shock or when concerned about acute lung injury, as it provides immune-modulating benefits beyond volume expansion 5
Avoiding excessive isotonic fluid resuscitation that may exacerbate the "bloody vicious cycle" of hypothermia, acidosis, and coagulopathy is crucial, according to Anaesthesia 5
Monitoring for excessive neutrophil-mediated tissue damage in organs like lungs, where persistent inflammation drives fibrosis, and considering the anti-inflammatory cytokine balance are important in autoimmune diseases 4

The American College of Physicians and other medical societies acknowledge that neutrophil recruitment to sites of inflammation follows a well-defined cascade that begins with the initial capture and rolling of neutrophils along the endothelial wall of blood vessels, which is mediated by selectins 6
The activated endothelium expresses adhesion molecules such as P-selectin and E-selectin on its luminal surface, which interact with ligands on neutrophils, promoting this initial rolling phase 6

The firm adhesion of neutrophils to the endothelial surface is mediated by the interaction between leukocyte integrins and endothelial adhesion molecules ICAM-1 and VCAM-1 6
N-cadherins are not significantly involved in neutrophil-endothelial interactions during inflammation 6
Complement activation may enhance neutrophil recruitment but is not directly responsible for the early rolling phenomenon 7, 8

Understanding the molecular mechanisms of neutrophil rolling has important clinical implications, as excessive neutrophil recruitment contributes to tissue injury and organ dysfunction in pathological conditions 6
Volatile anesthetics like isoflurane and sevoflurane have been shown to impair neutrophil adhesion to human endothelial cells, which may provide beneficial effects in ischemic settings 7, 9
These anesthetics bind to lymphocyte function-associated antigen-1 (LFA-1), blocking its interaction with ICAM-1 and inhibiting immune cell adhesion 9